


Promise

by MorganD



Category: Shadowhunters (TV), The Shadowhunter Chronicles - All Media Types
Genre: Fluff, Jalec Spring Break, M/M, Not Canon Compliant, Sensuality
Language: English
Status: Completed
Published: 2017-05-24
Updated: 2017-05-24
Packaged: 2018-11-04 07:56:48
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,288
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10986729
Author URL: https://archiveofourown.org/users/MorganD/pseuds/MorganD
Summary: Clary asks her friends a couple of questions about their runes.





	Promise

**Author's Note:**

> Some liberties were taken regarding the meaning of some less known runes.

Clary falls gracelessly on her butt, again.

Jace snorts. “You seriously need to stop getting distracted by my wonderful abs when we’re training.” He offers her his hand. “Or at all. You don’t want to give poor Simon a complex.”

Clary rolls her eyes, but accepts his help to get up. “Simon has nothing to worry about. Our relationship is just _fine_ , and so is his abs.”

“Right. So you were not distracted.”

“I was, but… Oh, wipe that smirk off! I was just wondering if that rune is going to vanish now.”

Jace blinks, looking down at his naked torso. “What? Which one?”

She points at the rune on the right side of his upper abs, a shape that vaguely reminds her of a flying seagull. “I mean, now that you know what happened to your father… and to your real father… and about everything Valentine did… and now that he’s gone for good… will your _promise_ rune disappear? After all, you did avenge your father in all the ways you could possibly avenge him… right? Or does it only work if you fulfill your promise verbatim?” She frowns in confusion. “That would make things very complicated…”

Jace chuckles. “Thankfully, it doesn’t really work like that. For starters, this rune is permanent. Which is why it’s only meant for the most sacred vows. It will never just _vanish_.” He touches the mark with gentle fingers. “The one thing that might destroy a _promise_ rune is actively breaking the promise you made. Not just failing to fulfill it, but truly acting against it.”

“I’m not sure I understand the difference.”

“Like… if you promise to defend someone’s life, and that person dies in spite of your very best efforts? Then you’re off the hook. It’s your commitment that counts. But if you somehow _cause_ that person to die, the rune will burn into a horrendous scar and take part of your soul with it.”

“Like when you lose a _parabatai_?”

Jace gulps, his shoulders suddenly rigid with tension. “I don’t know. Maybe. Either way, not the kind of pain I want to know. Ever.”

Clary nods. “Sorry. Didn’t want to bring the mood down.”

He shakes his head. “No problem. Rematch? Can you focus now, or do you need me to put on my hoodie?”

“Oh, shut your mouth.”

* * *

Clary adjusts the sleeves of her blouse nervously, and knocks on the door. “Izzy, can I come in?”

“Just a moment.”

“Alec asked me to tell you that the consul will be here any minute now, and that whatever it is you’re wearing, it’s good enough, so hurry up.”

After a few seconds, the door opens… to reveal a grinning Isabelle Lightwood wearing nothing but a maroon lace set of bra and panties. “Really?”

Clary bites her lower lip to suppress a giggle. “Maybe he underestimated the time you take to get dressed?”

“Actually, his estimate was not far off,” says Izzy, going back to her armoire while Clary enters the room and closes the door. “I thought I was ready five minutes ago.”

“What happened?”

Still with her attention focused on the contents of her armoire, Izzy points to her bed, where a black dress is laid out. “Found a stain on the hem. Don’t know what it is. Not mud or blood or ichor or any of the other usual fluids I get in touch with in a daily basis. I’ll have to examine it in the lab later.”

Clary sits down on the bed, at a cautious distance from the tarnished garment.

Izzy selects two other black dresses and shows them to Clary. “Which one would you never, never, _ever_ wear to meet the consul?”

Clary easily points to the one on the left, whose neckline seems deep enough to reach the waistline.

“Thanks.” Predictably, that’s the one Isabelle chooses to put on.

Clary doesn’t mean to stare, but it’s a lost battle. More even than Isabelle’s stunning beauty, it's the way she moves, completely comfortable in her skin, that never fails to hold Clary’s attention.

Looking at her friend’s runes, though, a troubled thought occurs to her. “Did I draw mine on the wrong place?” she murmurs to herself, rubbing her own right arm.

“What?”

A little thrown at the realization that she spoke out loud, Clary explains, “The rune for _courage in combat_. You have it on your back, behind your left shoulder. And I know Jace has it on the lower left side of his back, while Alec has it… I can’t quite remember the exact point, but it’s somewhere on his back, too. But I put mine on my right arm. Did I do it wrong?”

“Well, not _wrong_ ,” says Izzy, stepping into the form-fitting dress and pulling it up around her body. “There’s no wrong spot to place that rune, really. I mean, some runes can be placed strategically.”

“Like Alec’s _precision_ rune on his arrow-shooting arm?”

“Not just _precision_ , but _strength_ and _stealth_ , all to improve his archery skills. Plus _expectation_ on the arm that holds the bow.”

“ _Expectation_ … I never really understood the purpose of that one.”

“It’s a rune that reinforces your mental powers so… uh… well, it’s hard to explain. Especially because I don’t have one, and some runes you really just truly understand when you have them.” Izzy pulls up the zipper on her back as effortlessly as if it were on her front, and studies herself on the mirror. “The way Alec explains it, the rune helps you focus your mind so your body meets your expectations. Like, it makes clumsy or involuntary movements less likely.”

“But not impossible, right?” Clary tilts her head to the side, smiling at Izzy’s reflection. “I mean, I saw him walk right into a closed door last night.”

Isabelle laughs fondly. “My poor brother. The consul’s visit has got him even more uptight than usual.” She grabs a hairbrush and attacks her long black locks with vigor. “ _Expectation_ is _highly_ strategic. He drew it on his left arm… well, actually, it was Jace who drew it, but Alec chose the spot… so the rune would steady his bow. It certainly hasn’t turned him into a better dancer, that’s for sure.”

“Is that why you don’t have an _expectation_ rune?” asks Clary. “Because it only favors one part of your body?”

Izzy’s face turns serious, the movements of the brush losing speed as she becomes more pensive. “To be quite honest, it’s because that rune seems to be very… intense. Mentally speaking. It strengthens your muscles, but it can be really taxing on your mind. It literally changes the way your brain connects to that part of your body… and the change is permanent. So it’s really not a rune you should decide to draw on yourself on a whim.”

Clary nods. “What about _courage in combat_?”

“Yeah, that one can really go anywhere on your skin, it makes no difference in the way it affects you.”

“So all three of you having it on your backs is pure coincidence?”

“Just a matter of being pragmatic. It’s smarter to leave your arms for runes you’ll need to reactivate often, like _strength_ , _agility_ , _soundless_ , _heightened speed_ … and of course, _iratze_.”

“Oh… that makes sense.”

“Don’t worry about it, Clary,” says Izzy with a wink. “You still have plenty of space.”

“What about the _parabatai_ rune? Is it always placed on the left flank?”

“No, that’s really up to the pair making the vow. There’s a tradition to have both _parabatai_ draw it on the same spot on each other’s bodies, but even that is not mandatory. Of course, common sense suggests you shouldn’t put it on any part of your body that might be cut off in battle, so it usually goes on the torso. That way, if the mark is cut off, you’ll probably die anyway, so it makes no difference. I’ve heard of _parabatai_ that drew the mark on their shaved heads. That definitely works too.”

“And _promise_?”

“ _Promise_?”

“Yeah, I noticed both Jace and Alec have _promise_ drawn more or less on the same spot. I mean, Jace’s is a little higher, right below his right pecs…” Clary points to that relative spot on her own stomach. “And Alec’s is a little above his bellybutton, but more to the right.”

“…yeah.”

“Is that placement mandatory for that rune?”

Izzy lets go of her brush and fiddles with the ends of her hair. “No.”

“So… coincidence? Or maybe a case of monkey-see-monkey-do between _parabatai_?”

Isabelle shrugs. “It’s possible.”

“You don’t know?” asks Clary, frankly surprised. “I always thought you’d know absolutely everything about your brothers. Even more than themselves.”

Izzy turns to her with a small grin. “I usually do. But _promise_ …” She sits down beside her friend. “Clary, _promise_ is a very private rune. We don’t ask about it. Ever. Neither about the content of the promise nor about the placement on that person’s body.”

“Is it like a birthday wish that doesn’t come true if you tell people about it?”

“No, it’s nothing like that. It’s just…” Izzy takes Clary’s hands in hers, struggling to find the right words. “It’s more than just a promise, okay? It’s a solemn pledge, as binding as the _parabatai_ bond, except it’s a commitment you make to yourself. You can’t ask about someone’s _promise_ rune without violating that person’s intimacy. Do you understand?”

“I… I guess so, yes. But… Oh God, I think I really messed up.”

“What? What did you do?”

“I asked Jace about his.”

Izzy’s grip tightens around Clary’s fingers. “You did?”

“Yeah. I asked him if the rune would disappear now that the whole thing with Valentine is over.”

Isabelle blinks. “What do you mean?”

“I thought the rune might disappear now that he fulfilled his promise. Damn, I shouldn’t have said that I know what his promise was, should I? But it was just so obvious!”

It takes a moment for Izzy to react. “…I see. Well… what did Jace tell you?”

Clary’s eyebrows arch high on her forehead. “Actually, he took it really well. He explained to me how the rune works, that it stays on forever, as long as the promise is not broken.”

“…right.”

“And I guess that one can’t possibly be broken now, can it?”

Isabelle takes a deep breath. “Well. I suppose we’re good here.” She smiles at Clary. “Just please remember not to ask any more questions about anyone’s _promise_ rune. Okay? Especially Alec. He would be _beyond_ pissed, justifiably so. It would not be pretty.”

“Okay.” Clary smirks. “I bet you know what Alec’s promise is, though. You know _everything_.”

Izzy beams mysteriously. “Come on. Alec will have a cow if we’re not there when the consul arrives.”

* * *

Jace runs a finger down Alec’s chest, following the patterns cast on his warm skin by the streetlight entering through the blinds of the motel’s window. He feels content and more than a little sleepy, ready to lie down beside his _parabatai_ on the rumpled sheets, close his eyes, and let his mind be filled with pleasant dreams. However, as his hand reaches Alec’s stomach, a question comes to his mind. “Do you ever wonder what people think when they see this?”

“What?” Alec asks groggily. “My abs? My bellybutton? My… treasure trail?”

Jace giggles. “No, silly. _This_.” His finger draws a circle around Alec’s _promise_ rune.

“Hmmm… Don’t know.” Alec yawns, pressing his head deeper into the pillow. “They think I made a promise?”

“Yeah, but what did you promise?”

Alec’s eyebrows knit together in vague confusion. “You _know_ what I promised, Jace…”

“ _Other_ people, Alec. When they see you like this…”

“No one sees me like this but you.”

“When they see you shirtless… when they see that you have a _promise_ mark… do you ever wonder what they imagine your promise to be?”

“Ah. Who knows? Probably something reeeeeeally boring. Everybody thinks I’m boring. What’s a super boring promise?”

“I’d say it’s a vow to never, ever go against the orders of the Clave…”

“…but then my rune would have turned into an awful nasty scar a long time ago, thanks to you. No, must be something else. Something really tedious that I haven’t achieved yet…”

“Be elected consul?”

“That’s very ambitious. People usually find professional ambition exciting. Maybe I promised to… to cut my toenails every three weeks.”

Jace chortles, poking Alec on the ribs. “No one thinks you’re _that_ boring. Not even Clary.”

“What do _you_ think people think when they see my _promise_ rune, then?”

“Actually…” Jace stretches his body beside Alec’s, bringing their faces close together. “I think for most people, the first word that comes to mind when they think of you is ‘honorable’. So they probably think your promise involves some sort of self-sacrifice. In favor of your family, or of the higher good.”

“Hmmm… Wow. You really think so?”

“Yeah.”

“How disappointed they would be, then.” Alec rolls them over, shifting to lie fully on top of Jace, and kisses him tenderly. “No sacrifice, no higher good. Just me being completely selfish and letting myself have what I always wanted.”

Jace reaches down and places his palm on Alec’s _promise_ rune. “To be yours,” he whispers. “To have and to hold, in good times and in bad.”

“To be yours,” Alec replies, his hand resting on Jace’s own rune. “To love and to cherish, for as long as we both shall live.”

Jace devours Alec’s mouth in a deep, hungry kiss that drives their sleepiness away.

“You do realize Isabelle probably knows, right?” Alec murmurs when they pause to take a breath.

“Of course she knows,” Jace snickers. “Izzy knows _everything_.”

**Author's Note:**

> Written for Day 2 of Jalec Spring Break – Runes. 
> 
> You can find me on Tumblr as morgandeeyue.


End file.
